Conventional surge arresters include silicone carbide valve elements arranged in series with gaps such as that disclosed in U.S. Pat. No. 3,727,108--Surge Arrester, issued Apr. 10, 1973 and assigned to the assignee of this invention.
U.S. Pat. No. 4,100,588 discloses an arrangement in which varistors of the zinc oxide type, for example, are disposed inside a porcelain housing specially constructed to dissipate heat.